Prediction of Dislocation Cores in Aluminum From Density Functional Theory

2008

Christopher Woodward, D. R Trinkle, Louis Hector Jr, D. L Olmsted

Physical Review Letters 100(4), 5507 (2008)

The strain field of isolated screw and edge dislocation cores in aluminum are calculated using densityfunctional theory and a flexible boundary condition method. Nye tensor density contours and differential displacement fields are used to accurately bound Shockley partial separation distances. Our results of 5 – 7.5 Ang (screw) and 7.0 – 9.5 Ang (edge) eliminate uncertainties resulting from the wide range of previous results based on Peierls-Nabarro and atomistic methods. Favorable agreement of the predicted cores with limited experimental measurements demonstrates the need for quantum mechanical treatment of dislocation cores.